This invention relates to door mirrors for an automobile or other vehicle, and more particularly to a door mirror improved in reduced wind noise.
In general, an automobile has a pair of door mirrors (or exterior rearview mirrors) mounted on right and left sides thereof to provide a driver with a view of areas behind a vehicle body from each side. The door mirror includes a mirror body mounted at a front portion of a front side door or other position of the automobile through a support base and a support stay, and a mirror element is attached in the mirror body in such a manner that makes an angle of the mirror adjustable in vertical and lateral directions.
In the automotive door mirror constructed as described above, the mirror body projects to the sides of the vehicle body, and a front (surface facing frontward) thereof takes on various shapes, typically a shape having good aerodynamic property, i.e., with a ridge-like surface, a curved surface, or the like. However, airflow passing along a periphery of the mirror body is likely to generate wind noise of about 1-3 kHz like a whistle, and reduction of such noise has been in demand.
Among previously proposed solutions for such wind noise reduction known in the art are a plurality of recesses (adjacent uneven sections) provided on the periphery of the mirror body (housing) to generate vortices (breakup) in the airflow that passes, as disclosed in German Patent Publication No. DE 4039484 A1, and a large number of dimples provided on a back (surface facing frontward) of the mirror body (mirror box) which dimples are distributed partway from a vehicle body-side end of the back surface to generate vortices (disturbance) in the airflow that passes, as disclosed in Japanese Laid-Open Patent Application, Publication No. JP 8-132965 A (see FIG. 9).
The plurality of recesses or large number of dimples thus provided on the periphery of the mirror body however could utterly mar a beautifully designed appearance of the mirror body. Moreover, such a large number of dimples that must be integrally formed on the periphery of the mirror body would require a large number of spherical projections corresponding to the dimples to be formed on a cavity surface of an injection mold for the mirror body, and would thus necessitate such a difficult task of major design changes as forming the large number of spherical projections on the cavity surface after completion of the mold. In addition, the mold must have a separable structure with multiple parts so that the mold may open to eject the final casting.
It is thus an exemplified object of the present invention to provide an automotive door mirror that is capable of abating wind noise without marring a beautifully designed appearance of a mirror body thereof and that lends itself to injection molding of the mirror body.
An automotive door mirror according to one aspect of the present invention includes a mirror body mounted on a side of a vehicle body through a support base and a support stay, and a plurality of baffle rails extending along a front-rear direction of the vehicle body are provided on a periphery of the mirror body, at least on a surface opposite a side of the vehicle body.
With this door mirror, wind that sweeps along the periphery of the mirror body during driving of the automobile passes along the plurality of baffle rails to the end of the surface without deviating partway from the surface. Accordingly, the wind noise of about 1-3 kHz like a whistle, as has been conventionally recognized as a drawback, may be reduced. Further, the plurality of baffle rails may serve as an accent of patterning, so as not to mar the beautifully designed appearance of the mirror body.
In the above automotive door mirror, the mirror body may preferably be comprised of an injection-molded casting integrally formed of plastic (synthetic resin), and the baffle rails may be so provided as to extend along a direction in which the mold for the mirror body opens. With this automotive door mirror, an injection molding operation may be performed more easily. Moreover, the mold for the above mirror body may be prepared by making use of an existing mold for a mirror body having no baffle rail on the periphery thereof, as grooves corresponding to the baffle rails may be added into a cavity surface of the existing mold; therefore, the mold for the above mirror body may be manufactured with ease.
Other objects and further features of the present invention will become readily apparent from the following description of preferred embodiments with reference to accompanying drawings.